●クラスの利用

----------------------------------------------------------
/**
* クラスの利用
*
*/
public class Jankensimu {
public static void main(String args[]) {
int kekaT = 0;
int kekaH = 0;
int A = 0;
String te[] = { "グー", "チョキ", "パー" };
for (int i = 1; i <= 5; i++) {

// 太郎じゃんけん
int B = Janken.Taro(A,i);
// 花子じゃんけん
A = Janken.jankenclass();
// 勝敗判定
int C = Janken.shouhaiclass(B, A);

System.out.println(i + "回目");
System.out.println("太郎:" + te[B] +
" vs " + te[A] + ":花子");
switch (C) {
case 0:
System.out.println("太郎の勝ち");
kekaT++;
break;
case 1:
System.out.println("花子の勝ち");
kekaH++;
break;
case 2:
System.out.println("あいこです");
break;
}
System.out.println();
}
System.out.println("結果");
System.out.println("太郎:"+kekaT+"勝");
System.out.println("花子:"+kekaH+"勝");
}
}
----------------------------------------------------------
----------------------------------------------------------
/*
* クラス
*/
import java.util.*;
public class Janken {
public static int jankenclass() {
//花子じゃんけん
// 0は[グー],1は[チョキ],2は[パー]
Random gene = new Random();
int enemy = gene.nextInt(3); // (Math.random() * 3);
return enemy;
}
public static int Taro(int j,int i) {
// // 太郎じゃんけん
// 0は[グー],1は[チョキ],2は[パー]
// Random gene = new Random();
int t1[] = {0,1,2,0,1, 0,0,1,0,0, 0,1,2,1,2};
int t2 = t1[i * (j + 1) - 1];
return t2;
}

public static int shouhaiclass(int me, int enemy) {
int keka = 0;
if ((me == 0 && enemy == 1) || (me == 1 && enemy == 2)
|| (me == 2 && enemy == 0))
// System.out.println("勝ち!");
keka = 0;
if ((me == 0 && enemy == 2) || (me == 1 && enemy == 0)
|| (me == 2 && enemy == 1))
// System.out.println("負け!");
keka = 1;
if ((me == 0 && enemy == 0) || (me == 1 && enemy == 1)
|| (me == 2 && enemy == 2))
// System.out.println("あいこ!");
keka = 2;
return keka;
}

}
----------------------------------------------------------

●整数を2進の文字列に変換

--------------------------------------------------
public class toBinaryStringDemo {
public static void main(String args[]){

for(int i=1; i < 16; i++){
String s = Integer.toBinaryString(i);
System.out.println(i + " " + s );
}
}
}
--------------------------------------------------
●整数を16進の文字列に変換
toHexString()

--------------------------------------------------
public class toHexStringDemo {
public static void main(String args[]){

for(int i=1; i < 40; i++){
String s = Integer.toHexString(i);
System.out.println(i + " " + s );

}
}
}
--------------------------------------------------